292 THE RUBBER INDUSTRY 



and principally confined to the higher grades. While 

 this reduced output may retain a premium in value for 

 some years to come over the Oriental product, for 

 reasons hereafter explained, its importance as a factor 

 influencing market prices will decline in direct propor- 

 tion to the progress of the plantation industry, and the 

 occasion for its use in the manufacture of rubber goods 

 will practically become a negligible quantity within the 

 next decade. It will become a luxury instead of a 

 necessity. 



The subject of the area under cultivation and the 

 steady increase in production leading up to the existing 

 conditions of to-day has been dealt with in detail in 

 the description of the principal centres of the industry 

 in the East. It is unnecessary, therefore, to recapitulate 

 more than the returns for 1912 and 1913, to demon- 

 strate clearly the expansion of the output and the close 

 relation of the increased quantity to the shrinkage in 

 the market value. The Oriental shipments for the past 

 two years are shown in the table on p. 293. 



In regard to future production, the yield has been 

 calculated until 1919 upon the acreage planted in 1912, 

 and leaving out of account any returns from areas 

 planted after that date. Under these conditions, the 

 total acreage on which production is based in 1919 will 

 comprise trees averaging ten years of age, equal in girth 

 and height to trees of twenty to twenty-five years 

 old in the Amazon Valley. Doubtless with increased 

 development a greater yield will be obtained than at 

 ten years, but for practical purposes the trees may be 

 considered as having reached maturity, and the quality 

 of the latex will show little difference in regard to 

 density after that period is passed. 



